Unloading machine



July 3, 1928. 1,676,041

S. NAGAO UNLOADING MACHINE Filed Dec. 16, 1925 6'Sheets Sheet 1 July 3,192& 1,676,041

S. NAGAO UNLOADING MACHINE" Filed Dec. 16. 1925". s Sho'ts-Sheet HTTORrvE July 3, 1928. 1,676,041

. 1 s. NAGAO UNLOADING' mourns FiiQdiDec. 16, 1925 3 Sheets- Sheet 3HT?! 0 IR nrEYS.

Patented July 3, 1928 UNITED STATES sETUno NAGAO, or TOKYO, JAPAN.

UNLOADIN G MACHINE.

Application filed December 16,1925, Serial No.'75,705, and in JapanDecember 17, 1924.

Unloading machines, the principal object of the invention being toprovide a machine of this character having a traveling grab incombination with a chute automatically movable into the path of movementof the grab for receiving material discharged from the grab and out ofsaid path for permitting free passage of the grab, whereby the speed ofoperation, and consequently the capacity of the machine, is greatlyincreased.

lVith the foregoing and other objects in view, which will appear as thedescription proceeds, the invention consists in the novel features ofconstruction and combination of parts which will 'be more fullydescribed hereinafter and particularly pointed out in the claims.

In thedrawings accompanying and formingrpart of this specification,

Fig. 1 is a side elevation of a traveling crane equipped with theimproved unloading'apparatus in posit-ion for unloading a barge, thedotted lines indicating the operative position of the chute;

Fig. 2 is a front elevation of the view shown in Fig. 1;

Fig. 3 is a plan view thereof;

Fig. 4: is a front view, on an enlarged scale, of the improved unloadingdevice proper Fig. 5 is a side view thereof, showing the device brokenaway from the crane;

Fig. 6 is a fragmentary front view showing the means for connecting thegrab and counterweight for movement together;

Fig. 7 is a fragmentary side view illustrating the operation of saidconnecting means; and

Fig. 8 is a plan View thereof.

The same characters of reference designate the same parts in thedifferent figures of the drawings.

Referring to the drawings, and especially to Figs. 1 and 2, theapparatus is shown carried by a crane 36, which is mounted on rollers soas to permit movement thereof in a direction parallel with the dock orother place of use, and which crane carries an inclined belt or conveyor32 for the disposal of material delivered by the grab, it beingunderstood that any other suitable form of conveyor may be used, sincethe conveyor is not a part of the present invention.

The unloading machine proper comprises a pair of vertical guide rails 7attached to the crane 36, between which rails is disposed a frame 13provided at its opposite ends with projections or shoes 16 and 17 in engagement with the rails 7 and adapted to travel vertically thereon.Suspended from the frame 13 is a grab 1, comprising a pair of jaws 14pivotally connected together by links 15 attached at their upper ends toa pulley 18 around which passes a main cable 11-, said cable passingover one of a pair of pulleys 20 mounted on the crane frame 36 andsecured on a Windlass 21. A second or auxiliary cable 12 passes over theother one of the pair of pulleys 20 and is secured at one end to thegrab frame 13.

In the crane frame 36, immediately back of the guide rails- 7, ispivotally mounted, as at 2 a chute 2 which is adapted to discharge intoa hopper 3. The chute is so mounted-that it will normally occupy aninclined position, with its upper end well in the path. of movement ofthe grab, as inclicated in dotted lines in Figs. 1 and 5. so that whenthe grab is in its elevated position any material discharged therefromwill fall onto the chute and be thereby delivered to the hopper 3. i

In orderto retain the chute 2 in vertical position while thegrab isbeinghoisted, and to insure the tilting of the chute at the proper time,I provide a counterweight 24 vertically slidable between the rails 7above the grab, said counterweight being connected with the chute by apair of cables 23 passing over pulleys 22 at the top of the crane frameand around pulleys 22 near the bottom of said frame, as shown clearly inFig. 5. The weight of the counterweight is such that when free to exertitself on the cables 23 the chute will be retained in vertical position.However, when the grab is being hoisted with a load of material, as itnears the top of the guide bars 7 the frame 13 engages the underside ofthe counterweight 24 and lifts it so that upon continued upward movementof the grab the counterweight is carried with it, thus slackening thecables 23 and permitting the chute 2 to swing into inclined posit-ionbelow the grab as shown in dotted lines in Fig. 5, whereupon the cable12 may be operated to open the grab thereby to discharge its contents onto the chute in a manner which will be read ily understood.

From the foregoing it will be obvious that the relative motion of thegrab and chute is of the utmost importance, especially after the grabhas discharged its contents and is being lowered; It will be understoodthat the grab descends quickly by gravity, and if it should happen thatthe chute has not entirely swung out of the way the grab would strikethe chute and thereby have its descent arrested. Consequently, I haveillustrated in Figs. 6,7 and 8 a mechanical device for preventing suchan accident. In this device two pairs of spring clamps'QG are secured-'to the counterweight 24 and provided. with clamping portions extendingtherebelow and adapted to straddle the shoes 16 of the frame 13 when thelatter is raised into contact with the counterweight, as shown clearlyin Figs. 6 and 7. The shoes 16' are preferably formed with double wedgeshaped cam surfaces, as shown in Fig. 7, for

engagement with the spring clamps, so that when the grab is being raisedsaid surfaces will first spread apart the clamps, which, after passingover the highest points of the Wedges will spring inward and engage thelower inclined surfaces thereof, so that when the grab starts downwardit carries the counterweight with it until further descent of thecounterweight is stopped by the cables 23 after the chute has arrived atits vertical position, whereupon the spring clamps will again be spreadby the cam surfaces of the grab shoes and thus release the grab from thecounterweight and permit continued descent of the grab.

Having thus described my invention, what I claim is:

1. In an apparatus of the character de-, scribed, the combination of avertically movable grab, a pivoted chute adapted to swing into aninclined position intersecting the path of movement of the grab, acounterweight disposed above the grab and adapted to be moved therebyduring its upward movement, means connecting said counterweight withsaid chute whereby the latter is normally retained in vertical positionout of the path of the grab and is automatically released when thecounterweight is raised, and cooperating means carried by said grab andcounterweight for resiliently connecting them together whereby the grabwill carry thecounterweight with itduring a portion of the downwardmovement of the grab.

2. In an apparatus of the character described, the combination of avertically movable grab, a pivoted chute adapted to swing into aninclined position intersecting the path of movement of the grab, acounterweight disposed abovethe grab and adapted to be 7 moved therebyduring its upward movement, means connecting said counterweight withsaid chute whereby the latter is normally retained in vertical positionout of the path of the grab and is automatically released when thecounterweight is raised, spring clamps carried by said counterweight andextending below the same, and cam members carried by said grab andadapted to be engaged by said spring members thereby to cause movementof the counterweight with the grab during a portion of its downwardmovement.

In testimony whereof I afix my signature.

' sETURo NAGAO.

